How Do You Go to the Toilet in Space?

If you can physically touch it, then gravity is working upon it. It's that force, invisible to the naked eye, which holds all matter together.  But we can see its effect. 

Drop a stone from your hand and it will plummet to the ground. Jump into the air and you'll soon be returned to your feet.

This is because our planet is using gravity to keep us close.  The bigger the matter, the greater its gravitational pull. Planet Earth is the biggest ball of matter in our vicinity. Eat all the hamburgers you want, you'll never be larger.

Even the moon up there can't counteract the gravitational force of the Earth. It's too small. But it tries. Oceans swish back and forth, like our seabeds are little more than gigantic bowls, as the water tries to reach the moon. It won't fly off into space. Even here the Earth keeps it close. It rises up and down shorelines instead, high tide and low tide corresponding to wherever the moon is orbiting in the sky.

But get far enough way from the Earth and that gravity field weakens. It's still there, because the gravity field is infinite. Those on the International Space Station (ISS) are far enough away from our planet to encounter what happens next. They are effectively in free-fall towards the Earth. Their bodies, and all of the tools and apparatuses that they use, appear and act weightless. This is Zero Gravity.

So how then, amidst all this wonder, do they clip their toe nails?

With such an enclosed system, as on the ISS, there is no way for matter to escape. It's imperative that nothing is allowed to drift through the air, which could endanger the astronauts on board.

Nail clippings can choke. Scissors can put eyes out. Larger objects might cause a nasty crack on the head.  But other things could be downright toxic.

Human waste is expelled from the body for a reason. Allowing vomit, excrement or urine to drift away at will could easily lead to astronauts becoming quite sick. It could enter the eyes, causing infection. It could be breathed in leading to a stomach upset at least. At worst, we're looking at typhoid or cholera.

It's not just the 'ewwww' factor, which makes people want to control those bodily fluids in space. It's plain health and safety.

Liquids form as droplets in the air, or else they are bound by their surface tension to the nearest larger object.

Both phenomena were demonstrated in the YouTube video above, when Canadian astronaut Chris Hadfield attempted to wring out a water drenched towel on the ISS. While some droplets did drift away, he was able to retain much of the water on his hands and wash-towel. He was just careful not to break the surface tension.

This is precisely how astronauts wash their hair, as shown in the footage below.  In the first, Mike Fossum talks us through the process. It's fascinating and quite wonderful, but immediately begs the question - how do you wash LONG hair in space?

Fortunately astronaut Anousheh Ansari also allowed her ablutions to be filmed aboard the ISS. The answer is - patiently!

The first issue for any astronaut answering a call of nature is their own weightlessness. They can't just sit down on the toilet and emit a sigh of relief. They'd float off again.

It all requires training back on Earth, plenty of practice, then a bit of preparation while on board the ISS. More than anything, it demands a perfect aim.

Our desperate astronaut slips his or her feet into the foot slots. It provides the anchorage to brace themselves in place. Two foam covered handles can be maneuvered across their thighs to help pin themselves onto the toilet bowl. Some astronauts simply reach up and hold onto the ceiling as well.

A clear plastic bag is inserted into the silvery receptacle to their side. It's ready to receive any tissues. Such things cannot be dropped into the bowl beneath them.

Then it's decision time. Number one or number two? They can't happen together, because each is collected and disposed of in different ways. In order to urinate, the male astronauts take a tube attached to the unit. It's placed over their anatomy and they are good to go.

A light flow of air persuades the urine droplets to continue down the tube, instead of floating away. The suction cannot be too great, as that would cause the poor gentleman an injury.

For female astronauts, the method is nearly the same, except they have further choices before they begin. Three different funnels may be attached, each shaped slightly differently in order to gain the closest match. For the ladies, the key here is to position the funnel snug against them. They haven't anything to insert into the tube, unlike the men!

Even more problematic are bowel movements. With the astronaut's rear end pressed as tightly to the toilet seat as possible, they are able to expel their waste. However, they are aiming at a hole just four inches in diameter. This takes a lot of practice to get right!